your code is for the rear wheel speed sensor. Easiest way to look for the problem would be to drive the vehicle with a scanner graphing the wheel speed sensors. all the sensors should read the same speed. your speedo may look normal but how does the speed match up against the front wheel speed sensors? The speedometer is not an actual counter off the VSS. It's more like an average. It smooths over erratic values that there might be to give you a smooth steady needle on the gauge. The pcm converts the ac signal from the vss to a 128k/mile so the ecmb can figure out the wheel speed of the rear wheels.

the code will set if the ecmb sees an open or short for 500ms. or a variation of an erratic wheel speed sensors for 200ms. or absence of a wheel speed sensor for 5 seconds, or if more that one sensor signal is absent for 120 seconds.